Born at Jerez de la Frontera in Andalusia, Spain; dates of birth and death uncertain.

The family were originally peasants and called themselves Alhaja until after the battle of Las Navas de Tolosa (11 July, 1212), when they were ennobled for service that contributed to the important victory which the kings of Castile, Aragon, and Navarre achieved over the Moors. One of the Alhajas informed the Christians of a mountain pass by which the position of the Arabs could be turned, and indicated the entrance by placing the skull of a cow near it. Hence the change of name and the coat of arms.

Alvar Nuñez joined the expedition of Pámfilo de Narvaez to Florida in 1526 as treasurer. With two other Spaniards and an Arab Moor, he was the only survivor who remained on the mainland. For eight years they roamed along the coasts of Louisiana and Texas under the greatest of hardships, their position among the Indians being wellnigh intolerable. In utter despair, Cabeza de Vaca at last tried his scanty knowledge of medicine and, his cures proving successful, he became a renowned medicine man among the natives, his companions following the example. The treatment to which they resorted partook of the nature of a faith-cure. He declares the sign of the cross to be a seldom-failing remedy. The belief of the outcasts in miracles was sincere, while acknowledging that they also employed indigenous Indian remedies with simple Christian religious ceremonials. After nine years they reached the Pacific coast in Sonora, Mexico, thus being the first Europeans to travel across the North American continent. Cabeza de Vaca arrived at the city of Mexico in 1536. He was also the first European who saw and described the American bison or buffalo. But the wanderers did not, as had been supposed, see the New Mexican pueblos. They only heard of them.

Returning to Spain in 1537, he obtained the post of Governor of the La Plata regions (Argentina), whither he went in 1541. Cabeza de Vaca was a trustworthy subaltern, but not fit for independent command. His men rebelled against him in 1543, took him prisoner, and sent him to Spain, where for eight years he was kept in mild captivity. The date of his death is not known, but it is stated that he ended his days at Seville, where he occupied an honourable and modestly lucrative position in connection with the American trade.

He wrote two works. One is the story of his first trials in America as a member of the expedition of Narvaez, which was published at Zamora in 1542, and is known under the title of Naufragios (reprinted 1555 and several times translated into English); the other is on his career in South America (published 1555) and called Comentarios. Both are valuable for the history of Spanish colonization, the former also for the customs and manners of North American Indians.

There is hardly a work on the history of North America extant that does not allude, more or less correctly, to Cabeza de Vaca, and the same may be stated in regard to histories of Argentina and Paraguay. The earliest publications are of course those written by himself, his La Relacion que dio Aluar Nuñez Cabeza de Vaca de lo acaescido en las Indians en la armada donde yua por gouernador Pamphilo de Narbaez etc. (Zamora, 1542), only two copies of which are known to exist, and La Relacion y comentarios del gouernador Aluar Nuñez Cabeza de Vaca (Valladolid, 1555).

OVIEDO, Hist. general y natural (Madrid, 1850), gives the text of the above with some modifications, adding a communication written while on the way to Europe. In Documentos inéditos de Indias, there are a few more documents; RAMUSIO, Delle Navigazioni e Viaggi (Venice, 1556), an Italian version. There is a French translation by TERNAUX COMPANS, both of the Naufrages and the Commentaires. English translations: PURCHAS, His Pilgramage (London 1625-26, title, Relation of the Fleet in India, whereof Pamphilus Naruaez was Governor); SMITH, tr. (Washington, 1851): reprinted by John Gilmary Shea (New York, 1871). A paraphrase of the work has been given by KINGSLEY, Tales of Old Travels (London, 1869). FANNY BANDELIER has published the journey of Alvar Nuñez Cabeza de Vaca (New York, 1905), a translation of the 1542 edition of the Naufragios.